Venetian blind ladder-cap and assembly



Dec. 23, 1969 H. K. LORENTZEN ET AL 3,485,286

VENETIAN BLIND LADDER-CAP AND ASSEMBLY Filed May 27, 1968 INVENTOR HANSK- LORENTZEN BY LEO ABATE ATTORNEY United States Patent O f 3,485,286VENETIAN BLIND LADDER-CAP AND ASSEMBLY Hans K. Lorentzen, BrickTownship, and Leo Abate, Wayne, N.J., assignors to Levolor Lorentzen,Inc., Hoboken, N..I., a corporation of New Jersey Filed May 27, 1968,Ser. No. 732,144 Int. Cl. E06b 9/38 US. Cl. 160-178 13 Claims ABSTRACTOF THE DISCLOSURE The lower end-portions of a Venetian blind ladder andassociated lift cord are attached to a hollow Venetian blind bottom bar.A one-piece plastic ladder-cap is adapted to be fastened to the bottombar in the region of the ladder and lift cord. The plastic ladder-capunderlies the bottom bar and extends upwardly in front and in backthereof. The ladder cap is provided with homogeneous plastic studs whichproject through tight stud-receiving holes in the bottom wall of thebottom bar and thereby fasten the ladder cap to the bottom bar. Theladder-cap has channels that are receptive of end portions of the ladderand lift cord.

BACKGROUND OF THE INVENTION A Venetian blind is customarily providedwith a bottom bar to which the lower end-portions of the longitudinalelements of the ladder are attached. A lift cord is often associatedwith a ladder, and the lower end-portion of the lift cord is alsoattached to the bottom bar.

The bottom bar has often been provided, in the region of the attachmentof the end portions of the ladder and associated lift cord, with eithera caplike fitting or an assembly that includes a caplike fitting. Thecaplike fiting, or the assembly which includes it, may or may not have afastening function in connection with the attachment of the ladder and/or the lift cord to the bottom bar. The caplike element, which may betermed a ladder cap, underlies the bottom bar and shields the lowerend-portions of the ladder so that they do not pick up dust and dirtfrom a window sill. With some bottom bars the ladder cap similarlyprotects the lower end-portion of the associated lift cord from pickingup dust and dirt.

The prior-art ladder-cap constructions and arrangements have variousdisadvantages and limitations. Some are more complex and/or expensivethan is desirable. Some are for special forms of bottom bars and cannotreadily be adapted for other forms of bottom bars. Some involve assemblyprocedures which are less facile and speedy than is desirable. In mostinstances at least, the prior-art ladder-caps mar the window sill uponstriking the sill when the blind is fully lowered, Few of any of theprior-art ladder-caps mar the window sill upon striking the suited foruse with a narrow bottom-bar of small height, for example, a bottom barA" wide and tall.

As examples of the prior-art ladder-cap structures and arrangements, seeUS. Patents 2,114,057, 2,421,505, 2,502,028, and 2,520,109.

SUMMARY OF THE INVENTION The present invention provides a Venetian blindladder-cap, and assembly of ladder-cap and bottom bar, which affords thefeatures or aspects hereinafter set forth.

In accordance with the invention a plastic ladder-cap has plastic studswhich are adapted to project through tight stud-receiving holes in thebottom wall of a hollow Venetian blind bottom-bar and thereby attach aladder cap to the bottom bar. In accordance with one aspect of theinvention, the ladder-cap includes a plastic base to underlie the hollowVenetian blind bottom-bar and also Patented Dec. 23, 1969 includes frontand rear plastic walls, homogeneous with the plastic base, to extendupwardly from the base and lie alongside the front and rear walls of thehollow Venetian blind bottom-bar.

In accordance with a feature of the invention, the ladder cap hasoutwardly-projecting plastic ribs that are homogeneous with the frontand rear plastic walls of the ladder cap and which extend across theends of the plastic base and thence upwardly across the front and rearplastic-walls.

In accordance with another feature of the invention, the ladder cap haschanels that extend downwardly in the front and rear plastic-walls ofthe ladder cap and thence toward each other in the plastic base of theladder cap, to afford passage for the lower end-portions of the frontand rear longitudinal-elements of a Venetian blind ladder. In accordancewith a further feature of the invention, the plastic base of the laddercap has a lengthwise-extending channel which merges with the twodownwardly-extending channels and which afford space receptive of theend portion of a ladder-associated lift-cord of a Venetian blind.

In accordance with other features of the invention, there are twoplastic studs which extend upwardly from the base of the ladder cap onthe longitudinal center-line thereof, these studs being at least roughlyaligned vertically with the mid portions of the plastic ribs that extenddownwardly from the ends of the ladder cap and these studs projectingthrough stud-receiving holes in the hollow bottom-bar in tight-fittingrelationship therewith and thereby fastening the ladder cap to thebottom bar.

In accordance with further features of the invention, the plastic studsof the ladder cap are solid studs of initially-circular cross sectionand the stud-receiving holes in the bottom bar are circular except forflat opposite sides. In accordance with other aspects the initialdiameter of the plastic studs is less than the diameter of thestud-receiving holes as measured between arcuate portions thereof butgreater than the diameter of the studreceiving holes as measured betweenthe opposite flats thereof.

In accordance with still another feature of the invention, the bottombar is of sheet metal and the metal at the fiat sides of thestud-receiving holes is rough and barblike, digging into the plasticstuds and opposing withdrawal of the studs once they have been insertedinto the stud-receiving holes.

The presently-preferred embodiment of the invention affords all of theforegoing features and aspects, and affords additional features andaspects that will be apparent from the drawing and the descriptions inconnection therewith. It is left to the user to decide upon the omissionof any feature or features, and/or aspect or aspects, which are notneeded for his particular use.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings the thickness of thesheet material may be exaggerated in some instances. FIGS. 3-10 aredrawn to approximately twice the scale of FIGS. 1 and 2. FIGS. 11 and 12are greatly enlarged, being to a much larger scale than any of the otherfigures.

As a Venetian blind is opened and closed, the bottom bar tilts forwardlyand rearwardly with the forward and rearward tilt of the slats. Forsimplicity, the drawings are on the basis of the bottom bar being in theuntilted position, i.e. in the position in which the front and rear ofthe bottom bar are at the same level.

FIG. 1 is an isometric view showing the plastic laddercap alone, thisview showing the cap right-side-up with the plastic studs projectingupwardly for upward insertion into the stud-receiving holes in thebottom wall of a hollow Venetian blind bottom-bar.

FIG. 2 is an isometric view of the plastic ladder-cap alone, turnedupside-down.

FIG. 3 is a fragmentary front elevation showing the bottom-bar andladder-cap, the ladder-cap of FTGS. 1 and 2 being attached to the bottombar.

FIG. 4 is a fragmentary plan view of the bottom bar and thereto-attachedladder-cap, looking from the top of FIG. 3.

FIG. 5 is a vertical cross-section on the line 5-5 of FIG. 3, showingthe bottom bar in vertical section and showing the thereto-attachedladder-cap in end elevation.

FIG. 6 is a vertical cross-section on the line 6-6 of FIG. 4, showingboth the bottom bar and the theretoattached ladder-cap in verticalcross-section. For the sake of clarity the plastic stud of the laddercap is omitted; if shown it would be superimposed on the center one ofthe three holes that this view shows in the bottom bar.

FIG. 7 is a fragmentary section on the line 77 of FIG. 4, showing boththe bottom bar and the theretoattached ladder-cap in verticallongitudinal-section, the plastic studs of the ladder cap being shown inelevation.

FIG. 8 shows the lower end-portion of a Venetian blind ladder and afragment of the associated lift-cord. These are to be attached to thebottom bar in association with the ladder cap. In FIG. 8 the ladder andlift cord are viewed as though looking down the length of the bottombar.

FIG. 9 is the same type of view as FIG. 8 but showing the ladderattached to the bottom bar, the bottom bar appearing in verticalcross-section.

FIG. 10 shows a fragment of the bottom bar in centrallongitudinal-section with the lower end-portion of the ladder-associatedlift-cord attached thereto.

FIG. 11 is a diagrammatic View illustrating the punch and die that areused to punch the stud-receiving holes in the bottom bar. The punch isshown in cross section and the die is shown in plan.

FIG. 12 is a schematic diagram illustrating the relationship between thestud-receiving hole in the bottom bar and the stud circle of the plasticstud of the ladder cap before the stud is inserted into thestud-receiving hole.

DESCRIPTION OF THE EMBODIMENT THAT IS PRESENTLY PREFERRED Except as maybe otherwise indicated, the description under this heading refers onlyto the particular form of the invention that is shown in the drawing.The drawing shows the presently preferred embodiment, i.e. the best modethus far contemplated of carrying out the invention.

When a Venetian blind is fully open the bottom bar is untilted, i.e. thefront and rear of the bottom bar stand at the same level. Forconvenience and clarity the bottom bar will be referred to hereinafteron the basis of its standing in untilted position. Similarly, the laddercap will be referred to hereinafter on the basis of its standing in theoriented position correspondig to the bottom bar being untilted.

The ladder cap is designated as a whole by 20; it is plastic and isinjection-molded in one piece. When molded the plastic is resilient andis fairly hard, whereby the ladder cap has good stability as regards itsconfiguration. At the same time, the ladder cap and the portions thereofare capable of a degree of resilient yielding. The presently preferredplastic is a resin sold by Phillips Chemical Company under the trademark Marlex and designated Marlex Resin TR822.

The ladder cap 20 includes a plastic base 21 and front and rear plasticwalls 22 and 23 which are homogeneous with the base and curve upwardlytherefrom, Homogeneous with the ends of the base 21 and with the ends ofthe walls 22 and 23, there are strengthening ribs 25 and 26 whichproject outwardly. These ribs have triangular end portions 25a, 25a and26a, 26a which extend above the upper edges of the front and rear walls22 and 23.

On the inside of the ladder cap, channels 27 and 28 extend downwardly inthe front and rear walls 22 and 23 and thence toward each other in thebase 21. A channel 29 extends lengthwise at the center of the base 21,and the channels 27 and 28 flare out and merge with the channel 29 asshown in the drawing. The plastic base 21 and the plastic walls 22 and23 are sheetlike and, in a ladder cap for a bottom bar which is wide andYe" tall, may have a thickness of approximately .035". Since the base 21and the walls 22 and 23 are sheetlike, the channels 27, 28, and 29 onthe interior of the ladder cap have counterparts on the exterior of theladder cap, viz, the ribs that are designated 27, 28', and 29'respectively.

Plastic studs 31 and 32 project upwardly from the plastic base 21 on theinside of the ladder cap. These studs are homogeneous with the base 21.The studs 31 and 32 are solid studs of cylindrical cross-section, theupper ends of the studs having the short tapers that are seen in thedrawing. The two studs 31 and 32 are located adjacent to the oppositeends of the base 21 of the ladder cap, the longitudinal axis of eachstud being vertical and passing through the longitudinal center line ofthe ladder cap. The two studs 31 and 32 on the inside of the ladder capare roughly aligned vertically with the mid portions of thestrengthening ribs 25 and 26 that are on the outside of the ladder cap.

The bottom bar is designated as a whole by 40. It is formed fromprepainted sheet steel and, for a bottom bar A" wide and /8" high, thesheet steel may be approximately .025" thick before painting. In crosssection the bottom bar has the oval configuration that is seen in FIGS.5, 6, and 9, the long axis of the oval being horizontal when the bar isuntilted. The bottom bar includes a bottom wall 41 from which front andrear walls 42 and 43 curve upwardly and merge with a top wall 44 thathas a central discontinuity at 45.

The Venetian blind has two or more ladders and associated lift cordswhich are attached to the bottom bar. To receive the end portions of aladder and the associated lift cord, the bottom wall 41 of the bottombar is provided with with a series of three transverse holes 45, 46, and47 plus a fourth hole 48. The holes 46 and 48 are midway between thefront and the rear of the bottom bar. The holes 45 and 47 are positionedas shown in FIG. 4, the centers of holes 45 and 47 lying on a line whichpasses through the center of hole 46 and which is perpendicular to thelongitudinal axis of the bottom bar. The bottom wall 41 of the bottombar is also provided with studreceiving holes 51 and 52 (FIG. 10) toreceive the studs 31 and 32 of the ladder cap. The holes 51 and 52 aremidway between the front and the rear of the bottom bar, which alignsthem with holes 46 and 48.

The holes 45, 46, 47, and 48 are circular holes punched in conventionalmanner, the punch moving from the outside to the inside of the bottombar 20. Each of the holes 51 and 52 is punched with a fiat-sided punchworking with a circular die, the punch also moving from the outside tothe inside of the bottom bar 20.

In FIG. 11 the die 60 has a circular opening 61 which receives the punch62 which is shown in cross section. Except for the flats at 62a, 62a thepunch 62 mates with the circular die opening 61 in conventional manner,with normal operating clearance. Flats 62a, 62a are cords of the punchcircle, the centers of the two cords lying on the same diameter of thepunch circle and the two cords being spaced from the die circle as seenin FIG. 11. In punching the holes 51 and 52 in the bottom wall 41 of thebottom bar, the die 60 is against the inner face of the bottom wall 41and the punch 62 is projected through the bottom wall 41 from theoutside to the inside of the bottom bar. Due to the abnormally-largeclearance between the circular opening 61 of the die and the flats 62a,62a of the punch, that metal of the bottom-bar wall 41 which is adjacentto the flats 62a, 62a is pushed toward the inside of the bottom bar; andas it is pushed it is roughened and torn, providing the holes 51 and 52with the rough barblike formations b, b that are seen in FIG. 10.

The Venetian blind ladder is designated as a whole by 70 and is of thetype that is known in the trade as a string ladder. The front and rearlongitudinal elements 72 and 73 are cordlike and are braided. The rungsor cross members 74 of the ladder each consists of a plurality ofseparate stringlike or threadlike strands which lie alongside oneanother. The lower ends of the longitudinal elements 72 and 73 aretipped with sheet-metal fittings 75. Each fitting 75 has a tubelikeportion 76 for approximately half its length and a channel-shapedportion 77 for the remainder of its length. The tubelike portion 76 istelescoped onto the end of the longitudinal element of the ladder andsqueezed against it, the metal of the tube being pricked inwardly atspots to securely attach the fitting 75 to the longitudinal element ofthe ladder.

In attaching the ladder 70 to the bottom bar the lower end-portions ofthe front and rear longitudinal elements 72 and 73 of the ladder arepassed downwardly around the front and rear walls 42 and 43 of thebottom bar, after which the fittings 75 are inserted tube end firstthrough the holes 45 and 47 in the bottom wall 41 of the bottom bar. Asthe fittings 75 are inserted through the holes 45 and 47, thelongitudinal elements 72 and 73 of the ladder nest within thechannel-shaped trailing-pop tions 77, 77 of the fittings. Once thefittings 75, 75 are inside of the bottom bar, the pull of thelongitudinal elements 72 and 73 at approximately the midpoint along thelength of the fittings 75, 75 causes the fittings to dispose themselvescrosswise of the holes 45 and 47 as seen in FIG. 9 and thereby preventfortuitous detachment of the ladder from the bottom bar.

The end portion of the lift cord 86 is passed downwardly through thehole 46 in the bottom wall 41 of the bottom bar and may then be knottedbeneath the bottom bar. In the alternative, the end porion of the liftcord 80 may be looped beneath the bottom bar and passed upwardly throughhole 48 to the inside of the bottom bar and then be knotted as is shownin FIG. 10.

With the ladder 70 and the lift cord 80 attached to the bottom bar, theladder cap 20 is applied. The studreceiving holes 51 and 52 in thebottom wall of the bottom bar are tight holes for the reception of theplastic studs 31 and 32.

FIG. 12 shows the relationship between each of the holes 51 and 52, andthe plastic stud to be received thereby. In FIG. 12 the full line Hrepresents the hole 51 or 52 (FIG. 10), these holes being circular inplan except for opposite flat sides at 62, 62' corresponding to theflats 62a, 62a of the punch 62. The dot-dash circle S in FIG. 12represents the circle of the solid cylindrical stud 31 or 32 before thestud is forcibly inserted into the hole 51 or 52. As is seen in FIG. 12,the relationship of the stud circle S to the hole H is such as toprovide marked interference between the stud and the fiat sides 62, 62of the stud-receiving hole, whereby the inserted stud will be intight-fitting relationship with the hole with slight clearance betweenthe stud and arcuate portions of the hole H.

The ladder cap is applied to the bottom bar by manually moving the base21 of the ladder cap toward the bottom wall 41 of the bottom bar withthe studs 31 and 32 in alignment with the holes 51 and 52 and thenforcibly projecting the studs 31 and 32 through the holes 51 and 52 tobring them, and the entire ladder cap 29, to the position that is bestseen in FIG. 7. As is seen in FIG. 7, the plastic studs not only passupwardly through the sheet-metal bottom wall of the bottom bar butextend well above such bottom wall. The tapered ends of the studs 31 and32 help start the studs into the stud-receiving holes 51 and 52. As thestuds are pushed into the holes, each stud is firmly squeezed betweenthe opposite fiat sides (62', 62 in FIG. 12) of the stud-receiving hole.These opposite flat sides of the holes have the rough barblikeformations that are designated by b, b in FIG. 10; and these barblikeformations dig into the walls of the plastic studs 31 and 32 and opposeremoval of the ladder cap. As shown in FIG. 7, the solid plastic studs31 and 32 are long enough to project well within the bottom bar when theladder cap is in position on the bottom bar.

The plastic studs 31 and 32 are resilient and fairly hard, and the gripof the stud-receiving holes 51 and 52 on the studs is so firm that thereis no danger of fortuitous separation of the ladder cap from the bottombar. However, if it is desired to remove the ladder cap from the bottombar, it can be done by inserting a knife or screw driver between thebottom wall 41 of the bottom bar and the base 21 of the ladder cap andprying the ladder cap from the bottom bar.

When the ladder cap 20 is in applied position on the bottom bar, thebottom wall 21 of the ladder cap underlies the bottom wall 41 of thebottom bar, and the front and rear walls 22 and 23 of the ladder capextend upwardly and lie alongside the front and rear walls 42 and 43 ofthe bottom bar. The lower end-portions of the longitudinal elements 72and 73 of the ladder, which extend around the bottom bar as seen in FIG.9, nest within the grooves 27 and 28 of the ladder cap. The portion ofthe lift cord which is beneath the bottom wall 41 of the bottom barnests within the longitudinal groove 29 in the ladder cap, whether thelift cord be knotted beneath the hole 46 in the bottom wall of thebottom bar or whether the lift cord be looped upwardly through the hole48 and then knotted as shown in FIG. 10. Since the longitudinal groove29 of the ladder cap extends in both directions from the centraltransverse plane of the ladder cap, in which plane the center of hole 46lies, the ladder cap could be turned end for end when applying it to thebottom bar and the groove 29 would still receive the portion of the liftcord which is beneath the bottom bar in FIG. 10.

When the bottom bar 40 is fully lowered toward a window sill, theengagement with the window sill is made by the plastic ladder cap 20which does not mar the sill. If the blind is in closed position at thetime, the bottom bar will be tilted either forwardly or rearwardlycorresponding to the tilt of the slats of the blind. However, the laddercap 20 will still protect the sill against marring since theoutwardly-protruding plastic ribs 25 and 26 of the ladder cap extendaround the front and rear walls 42 and 43 of the bottom bar. The ribs27' and 28' of the ladder cap also extend around the front and rearwalls 42 and 43 of the bottom bar and are interposed between the windowsill and the bottom bar when the bottom bar is tilted.

What we claim is:

1. A Venetian blind ladder-cap comprising:

a plastic base to underlie a hollow Venetian blind bottom bar,

front and rear plastic walls homogeneous with said plastic base andextending upwardly therefrom to lie alongside the front and rear wallsof the Venetian blind bottom-bar,

channels extending downwardly in the front and rear plastic walls andthence toward each other in the plastic base, to afford passage for thelower endportions of the front and rear longitudinal elements of aVenetian blind ladder, and 1 plastic studs homogeneous with said plasticbase and extending upwardly therefrom between said front and rearplastic walls to project through tight holes in the bottom wall of theVenetian blind bottombar and thereby secure the ladder cap to the bottombar.

2. A Venetian blind ladder-cap as in claim 1, which further comprises:

a channel extending lengthwise of the plastic base centrally thereof,

said lengthwise-extending channel merging with the channels of claim 3and affording space receptive of an end portion of a ladder-associatedlift-cord of a Venetian blind.

3. A Venetian blind ladder-cap comprising:

a plastic base to underlie a hollow Venetian blind bottom bar,

front and rear plastic walls homogeneous with said plastic base andextending upwardly therefrom to lie alongside the front and rear wallsof the Venetian blind bottom-bar, outwardly-projecting plastic ribs thatare homogeneous with the plastic base and with the front and rearplastic walls,

the plastic ribs extending across the ends of the base and thenceupwardly across the ends of the front and rear plastic walls,

channels extending downwardly in the front and rear plastic walls andthence toward each other in the plastic base, to afford passage for thelower endportions of the front and rear longitudinal elements of aVenetian blind ladder, and

plastic studs homogeneous with said plastic base and extending upwardlytherefrom between said front and rear plastic walls to project throughtight holes in the bottom wall of the Venetian blind bottom-bar andthereby secure the ladder cap to the bottom bar.

4. A Venetian blind ladder-cap as in claim 3 which further comprises:

a channel extending lengthwise of the plastic base centrally thereof,

said lengthwise-extending channel merging with the channels of claim 4and affording space receptive of an end portion of a ladder-associatedlift-cord of a Venetian blind. 5. A Venetian blind constructioncomprising: a hollow sheet-metal bottom-bar having stud-receiving holesin the bottom wall thereof,

said stud-receiving holes being circular except for opposite flat sides,and

a plastic ladder-cap attached to the bottom bar, the

ladder cap having plastic studs which project through saidstud-receiving holes in tight-fitting relationship therewith and therebyeffecting the attachment of the ladder cap to the bottom bar,

the studs being solid studs of initially-circular cross section.

6. A Venetian blind construction as in claim 5 in which the initialdiameter of the studs is less than the diameter of the stud-receivingholes as measured between arcuate portions thereof, but greater than thediameter of the stud-receiving holes as measured between the oppositeflat sides thereof.

7. A Venetian blind construction as in claim 6 in which the metal at theflat sides of the stud-receiving holes is rough and barblike, digginginto the plastic studs and opposing withdrawal of the studs.

8. A Venetian blind construction in which a bottom bar is attached tothe lower end of a ladder, the bottom bar is hollow and has front andrear sheet-metal walls and also has a sheet-metal bottom wall, and aladder cap is attached to the bottom barwherein the improvementcomprises:

the bottom bar has stud-receiving holes in the sheetmetal bottom wallthereof, the ladder cap has a plastic base which underlies thesheet-metal bottom wall of the bottom bar in overlapping relation to thestud-receiving holes therein,

the ladder cap has front and rear plastic walls which are homogeneouswith said plastic base and extend upwardly therefrom, overlying thefront and rear walls of the bottom bar, and

the ladder cap is attached to the bottom bar by resilient plastic studswhich are homogeneous with the plastic base of the ladder cap on theupper side thereof, said plastic studs passing upwardly through thestudreceiving holes in the sheet-metal bottom wall of the bottom bar andextending above such bottom well, said plastic studs having an initialcross section which extends beyond the margin of the studreceivingholes, and said plastic studs having been forcibly projected through thestud-receiving holes in the sheetmetal bottom wall of the bottom bar,whereby such stud-receiving holes firmly grip the plastic studs. 9. AVenetian blind construction as in claim 8 in which the improvementfurther comprises:

the plastic studs being initially circular in cross section and thestud-receiving holes being non-circular. 10. A Venetian blindconstruction as in claim 8 in which the improvement further comprises:

the margins of the stud-receiving holes having portions which are roughand barblike, digging into the plastic studs and opposing withdrawal ofthe studs. 11. A Venatian blind construction as in claim 8 in which theimprovement further comprises:

elongated plastic ribs which are homogeneous with the base of the laddercap on the under side thereof,

these ribs extending transversely of the base of the ladder cap andthence upwardly across the front and rear plastic walls of the laddercap, whereby these ribs are interposed between the bottom bar and awindow sill when the bottom bar is lowered toward the window sill andeven if the bottom bar be in tilted position. 12. A Venetian blindconstruction as in claim 8 in which the improvement further comprises:

downwardly-projecting plastic ribs which are homogeneous with the baseof the ladder cap on the under side thereof,

these ribs extending transversely of the base of the ladder cap adjacentto the ends thereof, the plastic studs being two studs located adjacentto the ends of the ladder cap, and

the two studs being vertically aligned, at least roughly, with saiddownwardly-projecting ribs on the under side of the base of the laddercap. 13. A Venetian blind construction as in claim 12 in which theimprovement further comprises:

the plastic ribs extending across the base of the ladder cap and thenceupwardly across the front and rear plastic walls of the ladder cap,whereby these ribs are interposed between the bottom bar and a windowsill when the bottom bar is lowered toward the window sill and even ifthe bottom bar be in tilted position.

References Cited UNITED STATES PATENTS Braun -173 PETER M. CAUN, PrimaryExaminer UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No3 ,485 ,286 December 23, 196

Hans K. Lorentzen et a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 1, lines 54 and 55, "Few of any of the prior-art ladder-caps marthe window sill upon striking the" should read Few if any of thepriorart ladder-cap structures and arrangements are well Column 2, line6, "plastic ribs" should read plastic-ribs line 12, "chanels" shouldread channels Column 3, line 55, "correspondig" should readcorresponding Column 7, line 2, the claim reference numeral "3" shouldread l line 11, the clause which commences with "outwardlyprojecting"should have been started on a new line coordinate with "a" in line 6 and"front" in line 8 of same column; line 32, the

claim reference numeral "4" should read 3 Signed and sealed this 15thday of December 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, J Attesting OfficerCommissioner of Patent

